吡草醚原药对大鼠胚胎及胎仔发育的影响

经口染毒大鼠检测妊娠动物接触吡草醚原药后引起致畸的可能性,初步评价吡草醚原药致畸危害程度。依据《GB15670-1995农药登记毒理学试验方法》,选用的大鼠按雄、雌2:1比例同笼交配,次日清晨阴道涂片检查雌鼠,发现精子即确定为受孕第0天,设低、中、高三个剂量组(18.56、92.80、464.00 mg·(kg·d)-1)、一个阴性对照组和一个阳性对照组。在雌鼠受孕第6~15天灌胃给予受试物,连续共10天,在妊娠第19.5天,处死孕鼠检查胚胎发育情况。高剂量组和阳性对照组大鼠孕期体重增重值降低,差异有显著性(p0.05);中、高剂量组和阳性对照组大鼠吸收胎率与阴性对照组比较差异有显著性(p0.05);中、高剂量组和阳性对照组胎鼠重量与阴性对照组比较,差异有显著性(p0.01);阳性对照组胎鼠外观畸形明显,与阴性对照组比较差异有显著性(p0.01);各剂量组胎鼠外观畸形与阴性对照组比较,差异均无显著性(p0.05);中、高剂量组组和阳性对照组胎鼠骨骼及内脏畸形例数明显增多,差异有显著性(p0.01)。实验结果表明吡草醚原药中、高剂量组可明显影响雌鼠体重增长及其胚胎的发育。     

Effects of bicarbonate and cathode potential on hydrogen production in a biocathode electrolysis cell

A biocathode with microbial catalyst in place of a noble metal was successfully developed for hydrogen evolution in a microbial electrolysis cell （MEC）. The strategy for fast biocathode cultivation was demonstrated. An exoelectrogenic reaction was initially extended with an H2-full atmosphere to enrich Ha-utilizing bacteria in a MEC bioanode. This bioanode was then inversely polarized with an applied voltage in a half-cell to enrich the hydrogen-evolving biocathode. The electrocatalytic hydrogen evolution reaction （HER） kinetics of the biocathode MEC could be enhanced by increasing the bicarbonate buffer concentration from 0.05 mol·L-1 to 0.5 mol· L-1 and/or by decreasing the cathode potential from -0.9 V to - 1.3 V vs. a saturated calomel electrode （SCE）. Within the tested potential region in this study, the HER rate of the biocathode MEC was primarily influenced by the microbial catalytic capability. In addition, increasing bicarbonate concentration enhances the electric migration rate of proton carriers. As a consequence, more mass H＋ can be released to accelerate the biocathode-catalyzed HER rate. A hydrogen production rate of 8.44 m3. m 3. d1 with a current density of 951.6 A. m-3 was obtained using the biocathode MEC under a cathode potential of - 1.3 V vs. SCE and 0.4 mol· L-1 bicarbonate. This study provided information on the optimization of hydrogen production in biocathode MEC and expanded the practical applications thereof.     

生命周期评价理论及其在污水处理领域的应用综述

生命周期评价为全面评价污水处理提供了工具。在介绍生命周期评价理论的基础上,对其在污水处理领域的应用理论进行分析,对其国内外应用现状和特点进行回顾性评价。同时展望了生命周期评价在污水处理领域的发展,并提出了意见和建议以推动生命周期评价在我国得到更好的应用。     

强震区小流域泥石流发育特征研究——以四川省绵竹市罗家沟泥石流为例

小流域泥石流因流域面积小,常被人们忽略或未引起足够的重视,却往往造成较大灾害损失;2010年8月13日绵竹市清平乡罗家沟暴发泥石流,一次冲出量约30万m3,而该沟流域面积仅1.4 km2;此次泥石流造成主沟沟口民房被掩埋,1.5 km的道路被毁,3座涵洞、一座小桥被冲毁,并使绵远河改道约200 m左右,直接经济损失约500万.根据现场调查和航空图像解译,分析了泥石流成因,讨论了泥石流形成、运动和堆积过程,并计算了泥石流的力学参数;罗家沟泥石流的实例表明汶川震区小流域泥石流具有较强的隐蔽性和破坏力.因此,在对汶川震区泥石流开展调查和评估工作时,尤其应注意小流域泥石流调查工作,必要时应进行相应的工程治理措施.     

Analysis of management effectiveness of natural reserves in Yunnan Province,China

Yunnan Province has many and unique natural resources and rich biodiversity. Natural reserves (NRs) play a significant role in maintaining and protecting the biodiversity and stability of ecosystems in this area. Yunnan is a typically eco-environmentally fragile area; thus positive effects of NRs are important in the construction of an ecological safety barrier for southwest China. Evaluation of the effectiveness of management of NRs has been implemented to improve management outcomes. This study provides indices to evaluate problems and management effectiveness for 60 NRs, covering national and provincial NRs of Yunnan Province. These indicate that management of NRs suffers from inadequate funding, poor infrastructure and equipment, low community participation, and a lack of government support. The indices had relatively low scores for infrastructure and equipment, ecotourism, monitoring, and evaluation, but high scores for planning and design and ownership. There were significant positive correlations between protection rank, size, age of NRs, and management effectiveness. International exchanges and collaboration would help to improve management of the NRs. NRs that straddle administrative boundaries had relatively higher scores than those within an administrative unit. Management success was not correlated with staff input, which might imply low efficiency of staff in this area. Some recommendations are offered to improve management of NRs based on analysis of management problems and identification of influencing factors.     

铀胁迫对两种蓝藻生长及抗氧化酶活性的影响

研究了不同浓度铀(0.1、1.0、10.0和30.0mg·L-1)胁迫对满江红鱼腥藻(Anabaena azollae)和爪哇伪枝藻(Scytonemaj avanicum)生长及抗氧化酶活性的影响。结果表明,低浓度铀(0.1和1.0mg·L-1)条件下,两种蓝藻的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量均无明显变化;叶绿素a含量和可溶性蛋白质含量均较对照上升,表明低浓度铀对A.azollae和S.javanicum均未形成明显胁迫,对生长表现为刺激和促进作用。10.0mg·L-1浓度的铀对A. azollae的生长影响不大,对S. javanicum却产生了明显的抑制作用。30.0mg·L-1铀胁迫下,两种蓝藻中的MDA显著增加,抗氧化酶系统受到破坏,生长严重受阻。实验结果显示,A. azollae和S. javanicum的耐铀极限分别在10.0～30.0mg·L-1和1.0～10.0mg·L-1之间,A. azollae的抗铀性比S. javanicum强。     

奇异灾难面面观

2000年7月10日上午7时,菲律宾首都马尼拉郊外奎松市贫民区的一座垃圾山突然发出惊天动地的巨响,夹带着粘稠液体和刺鼻的异味崩塌了。山下的100多间棚屋顷刻间被埋得踪影全无,一个昏死过去的男子趴在垃圾堆上,救援人员赶紧过去想把他抬上担架送医院抢救,可他的一条腿被垃圾堆里的铁丝死死缠住丝毫动弹不得,而不远处还埋     

乌鞘岭隧道施工环境保护措施探讨

对乌鞘岭隧道施工过程中的环境保护措施进行了探讨,对施工过程中产生的水污染、大气及洞内空气污染、固体废弃物污染、噪声污染、植被破坏等采取了相应的措施,取得了良好的效果。     

惊天霹雳点燃大油库

16年前的1989年8月12日,青岛市黄岛油库因遭雷击引发了建国以来最大的一起油库大火,震憾了国内外。在突如其来的灾难面前,在生与死、血与火的考验面前,我和广大消防官兵一起战斗104个小时,终将大火扑灭。火灾带来的教训是沉痛的。在16年后的今天,回头再看那场惊心动魄的大火,还会带给我们深深的思索。     

Size fractionation and characterization of nanocolloidal particles in soils

A protocol was developed to fractionate soil particles down to the nanocolloid scale by combining sieving, sedimentation, centrifugation, and cross-flow filtration (CFF). The validity of the method and the performance of the CFF system were tested by characterizing fractions using laser granulometry, electron microscopy, and chemical analysis. The 0.1-μm-pore-size membrane CFF system effectively retained nanocolloids (<0.1 μm) as shown by laser granulometry and observed directly by transmission electron microscopy. However, environmental scanning electron microscopy images of freeze-dried colloids were very different from their TEM counterparts, suggesting that sample preparation influenced microscopy imaging. Chemical analysis of Cu, Cd, and organic carbon in each fraction showed that the concentrations of these components increased as particle size decreased, indicating colloids and nanocolloids play an important role in retaining trace metals. Particle-size fractionation combined with chemical analysis and electron microscopy can provide insight into the nature and properties of nanocolloids in soil.